Gelatin–alginate–hyaluronic acid inks for 3D printing: effects of bioglass addition on printability, rheology and scaffold tensile modulus

Abstract

Natural hydrogels are widely used for 3D-bioprinting because of their qualities fortissue engineering. Recently, hydrogels have been combined with bioactive glasses,due to their angiogenic properties that aid tissue regeneration. In this work, we studiedthe printability and rheological properties of gelatin-alginate-hyaluronic acid inks with 2to 8 % w.w-1 of 45S5 bioglass (BG) that followed a pseudoplastic behavior along the3D-printing process. The reduction of the storage modulus of the inks after adding BGindicates that the microparticles might disrupt the polymeric network; furthermore, areduction of the viscosity was determined at BG concentrations above 6%. Inks withoutBG or up to 2 % evidenced the best printing fidelity on 10 % infill scaffolds. The tensilemodulus of crosslinked 40 %-filled scaffolds increased from 130 kPa (without BG) to160 kPa (6 to 8 % BG). Moreover, scaffolds containing BG 6 % and 8 % w.w-1presented a hydroxyapatite layer after being cultured for 2 days. Attachment andgrowth of fibroblasts on the scaffolds revealed their cytocompatibility, making thesematerials an alternative for further research on soft tissues regeneration.